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D J Bissonette

Publications and source records attributed to D J Bissonette.

36 records · Page 2Linked to original sources
PubMed1995

Microvascular decompression for hemifacial spasm.

The authors report the results of 782 microvascular decompression procedures for hemifacial spasm in 703 patients (705 sides), with follow-up study from 1 to 20 years (mean 8 years). Of 648 patients who had not undergone prior intracranial procedures for hemifacial spasm, 65% were women; their mean age was 52 years, and the mean preoperative duration of symptoms was 7 years. The onset of symptoms was typical in 92% and atypical in 8%. An additional 57 patients who had undergone prior microvascular decompression elsewhere were analyzed as a separate group. Patients were followed prospectively with annual questionnaires. Kaplan-Meier methods showed that among patients without prior microvascular decompression elsewhere, 84% had excellent results and 7% had partial success 10 years postoperatively. Subgroup analyses (Cox proportional hazards model) showed that men had better results than women, and patients with typical onset of symptoms had better results than those with atypical onset. Nearly all failures occurred within 24 months of operation; 9% of patients underwent reoperation for recurrent symptoms. Second microvascular decompression procedures were less successful, whether the first procedure was performed at Presbyterian-University Hospital or elsewhere, unless the procedure was performed within 30 days after the first microvascular decompression. Patient age, side and preoperative duration of symptoms, history of Bell's palsy, preoperative presence of facial weakness or synkinesis, and implant material used had no influence on postoperative results. Complications after the first microvascular decompression for hemifacial spasm included ipsilateral deaf ear in 2.6% and ipsilateral permanent, severe facial weakness in 0.9% of patients. Complications were more frequent in reoperated patients. In all, one operative death (0.1%) and two brainstem infarctions (0.3%) occurred. Microvascular decompression is a safe and definitive treatment for hemifacial spasm with proven long-term efficacy.

Adolescent↗
PubMed1994

Long-term results after glycerol rhizotomy for multiple sclerosis-related trigeminal neuralgia.

Percutaneous retrogasserian glycerol rhizotomy (PRGR) was used during an 11-year interval in 53 patients with typical trigeminal neuralgia associated with multiple sclerosis. All patients had failed extensive medical trials prior to PRGR. Long-term (median follow-up, 36 months) complete pain relief (no further medication) was achieved in 29 (59%) of 49 evaluable patients. Eight patients (16%) had satisfactory pain control but required occasional medication. Twelve patients (25%) had initial unsatisfactory results with inadequate pain relief; nine underwent alternative surgical procedures. Sixteen patients (30%) subsequently required repeat glycerol rhizotomies to reachieve pain control. Twenty-seven patients (60% of 45 patients evaluated for this finding) retained normal trigeminal sensation after injection. Major trigeminal sensory loss developed in a single patient who had four glycerol rhizotomies over a 25-month interval. No patient developed deafferentation pain. We believe that PRGR is a low-morbidity, effective, and repeatable surgical procedure for the management of trigeminal neuralgia in the setting of multiple sclerosis.

Female↗
PubMed1993

Radiosurgery for vascular malformations of the brain stem.

The challenges associated with microsurgery of vascular malformations located in the midbrain, pons and medulla have promoted the development of alternative therapeutic techniques. To assess the efficacy and safety of radiosurgery in the management of brain stem vascular malformations we reviewed our 5-year experience in 50 patients evaluated between 4 and 51 months (mean, 25 months) after radiosurgery. Twenty-eight patients (56%) underwent gamma unit radiosurgery for symptomatic arteriovenous malformations (AVMs), and 22 patients (44%) for angiographically occult vascular malformations (AOVMs). Patients varied in age from 7 to 76 years (mean, 39 years). Forty-one patients (82%) had from 1 to 5 hemorrhages prior to gamma knife radiosurgery. Ten (20%) had one or two prior unsuccessful operations, and 37 (74%) presented with a neurological deficit. Of the patients with AVMs, 6 were considered Spetzler Grade III, and 22 (79%) Grade VI (inoperable: major component within the brain stem parenchyma). Forty-four malformations (88%) were adjacent to or within the midbrain and pons; the remainder involved the medulla. Average malformation diameters varied from 6 to 30.4 m (mean, 20.6; mean volume 4614 mm3). The minimal radiation dose to the margin of the malformations ranged from 12 to 25.6 Gy (mean, 18.9 Gy). Of the 28 patients with AVMs, 8 had follow-up angiograms at a minimum of 2-years after radiosurgery (or sooner if their MRIs suggested obliteration). Of these patients, 7 (88%) showed complete obliteration of their malformations. No patients with AOVMs rehemorrhaged if more than 15 months elapsed after radiosurgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Gamma knife surgery for sellar and suprasellar tumors.

Recent advances in neuroimaging, coupled with stereotactic delivery of ionizing radiation, permit precise, single-treatment irradiation of various intracranial tumors. This article describes the authors' experience with the 201-source 60Co gamma knife. Initial results indicate a potential therapeutic role for radiosurgery in controlling tumor growth and hormone hypersecretion in most patients. The authors believe that radiosurgery should be considered for small pituitary adenomas when prior microsurgery has failed to control tumor growth. Radiosurgery is a primary treatment alternative for patients who are elderly, medically infirm, or refuse microsurgical removal. Further follow-up is necessary to evaluate the long-term tumor control rate, hormonal effects, and tolerance of surrounding critical structures to stereotactic radiosurgery.

Adenoma↗
PubMed1992

Stereotactic radiosurgery of brain vascular malformations.

Stereotactic radiosurgery using the gamma unit was performed in 251 patients with brain vascular malformations in a 3-year interval. Our efforts include the identification of factors related to both success and complications, including analysis of the malformation location, volume, and dose used. Radiosurgery is a valuable alternative treatment for many patients with brain vascular malformations, including those currently believed to be poor surgical candidates.

Adolescent↗
PubMed1991

Radiosurgery of acoustic neurinomas.

Eighty-five patients with acoustic neurinomas underwent stereotactic radiosurgery with the gamma unit at the University of Pittsburgh (Pittsburgh, PA) during its first 30 months of operation. Neuroimaging studies performed in 40 patients with more than 1 year follow-up showed that tumors were smaller in 22 (55%), unchanged in 17 (43%), and larger in one (2%). The 2-year actuarial rates for preservation of useful hearing and any hearing were 46% and 62%, respectively. Previously undetected neuropathies of the trigeminal (n = 12) and facial nerves (n = 14) occurred 1 week to 1 year after radiosurgery (median, 7 and 6 months, respectively), and improved at median intervals of 13 and 8 months, respectively, after onset. Hearing loss was significantly associated with increasing average tumor diameter (P = 0.04). No deterioration of any cranial nerve function has yet developed in seven patients with average tumor diameters less than 10 mm. Radiosurgery is an important treatment alternative for selected acoustic neurinoma patients.

Adolescent↗
PubMed1991

Solitary brain metastasis: radiosurgery in lieu of microsurgery in 32 patients.

Thirty-two consecutive patients with 34 small brain metastases underwent boost stereotactic radiosurgery using the first North American Gamma Unit between May 1988 and July 1990. The majority of tumors (n = 24; 71%) were considered resistant to conventional, fractionated irradiation (malignant melanoma, n = 13; non-small cell lung carcinoma, n = 7; renal cell carcinoma, n = 4). During the follow-up period (median = 10 months; range = 1.5-15 months) no patient suffered a complication of radiosurgical treatment, and no patient died from a radiosurgically-treated metastasis. Shrinkage or growth-arrest was documented in 20 of 23 patients (87%) available for follow-up. Median survival after treatment was 10 months.

Adolescent↗
PubMed1991

Radiosurgery for solitary brain metastases using the cobalt-60 gamma unit: methods and results in 24 patients.

To define the role of stereotactic radiosurgery in the treatment of metastatic brain tumors we treated 24 consecutive patients (20 men, 4 women) with the 201-source 60Co gamma unit between May 1988 and March 1990. The primary tumors included malignant melanoma (n = 10), non-small cell lung carcinoma (n = 6), renal cell carcinoma (n = 3), colorectal carcinoma (n = 1), oropharyngeal carcinoma (n = 1), and adenocarcinoma of unknown origin (n = 3). All tumors were less than or equal to 3.0 cm in greatest diameter. Twenty patients received a planned combination of 30-40 Gy whole brain fractionated irradiation and a radiosurgical "boost" of 16-20 Gy to the tumor margins; one patient refused conventional fractionated irradiation. Three patients with recurrent, persistent, or new non-small cell lung carcinomas had radiosurgical treatment 12-20 months after receiving 30-42.5 Gy whole-brain external beam irradiation. Stereotactic computed tomographic imaging was used for target coordinate determination and imaging-integrated dose planning. All tumors were enclosed by the 50-90% isodose shell using one (n = 22), two (n = 1), or three (n = 1) irradiation isocenters. During this 23-month period (median follow-up of 7 months) no patient died from progression of a radiosurgically-treated brain metastasis. Ten patients died of systemic disease (n = 8) or remote central nervous system metastasis (n = 2) between 1 week and 10 months after radiosurgery. One patient had tumor progression and underwent craniotomy and tumor excision 5 months after radiosurgery. To date, median survival after radiosurgery has been 10 months; 1-year survival was 33.3%. Stereotactic radiosurgery eliminated the surgical and anesthetic risks associated with craniotomy and resection of solitary brain metastases. Radiosurgery also effectively controlled the growth of tumors considered "resistant" to conventional irradiation.

Adult↗
PubMed1991

Stereotactic radiosurgery for arteriovenous malformations of the brain.

Stereotactic radiosurgery successfully obliterates carefully selected arteriovenous malformations (AVM's) of the brain. In an initial 3-year experience using the 201-source cobalt-60 gamma knife at the University of Pittsburgh, 227 patients with AVM's were treated. Symptoms at presentation included prior hemorrhage in 143 patients (63%), headache in 104 (46%), and seizures in 70 (31%). Neurological deficits were present in 102 patients (45%). Prior surgical resection (resulting in subtotal removal) had been performed in 36 patients (16%). In 47 selected patients (21%), embolization procedures were performed in an attempt to reduce the AVM size prior to radiosurgery. The lesions were classified according to the Spetzler grading system: 64 (28%) were Grade VI (inoperable), 22 (10%) were Grade IV, 90 (40%) were Grade III, 43 (19%) were Grade II, and eight (4%) were Grade I. With the aid of computer imaging-integrated isodose plans for single-treatment irradiation, total coverage of the AVM nidus was possible in 216 patients (95%). The location and volume of the AVM were the most important factors for the selection of radiation dose. Magnetic resonance (MR) imaging was performed at 6-month intervals in 161 patients. Seventeen patients who had MR evidence of complete obliteration underwent angiography within 3 months of imaging: in 14 (82%) complete obliteration was confirmation being 4 months (mean 17 months) after radiosurgery. The 2-year obliteration rates according to volume were: all eight (100%) AVM's less than 1 cu cm; 22 (85%) of 26 AVM's of 1 to 4 cu cm; and seven (58%) of 12 AVM's greater than 4 cu cm. Magnetic resonance imaging revealed postirradiation changes in 38 (24%) of 161 patients at a mean interval of 10.2 months after radiosurgery; only 10 (26%) of those 38 patients were symptomatic. In the entire series, two patients developed permanent new neurological deficits believed to be treatment-related. Two patients died of repeat hemorrhage at 6 and 23 months after treatment during the latency interval prior to obliteration. Stereotactic radiosurgery is an important method to obliterate AVM's, especially those previously considered inoperable. Success and complication risks are related to the AVM location and the volume treated.

Adolescent↗
PubMed1990

Stereotactic radiosurgery of angiographically occult vascular malformations: indications and preliminary experience.

Stereotactic radiosurgery has been shown to treat successfully angiographically demonstrated arteriovenous malformations of the brain. Angiographic obliteration has represented cure and eliminated the risk of future hemorrhage. The role of radiosurgery in the treatment of angiographically occult vascular malformations (AOVMs) has been less well defined. In the initial 32 months of operation of the 201-source cobalt-60 gamma knife at the University of Pittsburgh, 24 patients meeting strict criteria for high-risk AOVMs were treated. Radiosurgery was used conservatively; each patient had sustained two or more hemorrhages and had a magnetic resonance imaging-defined AOVM located in a region of the brain where microsurgical removal was judged to pose an excessive risk. Venous angiomas were excluded by performance of high-resolution subtraction angiography in each patient. Fifteen malformations were in the medulla, pons, and/or mesencephalon, and 5 were located in the thalamus or basal ganglia. Follow-up ranged from 4 to 24 months. Nineteen patients either improved or remained clinically stable and did not hemorrhage again during the follow-up interval. One patient suffered another hemorrhage 7 months after radiosurgery. Five patients experienced temporary worsening of pre-existing neurological deficits that suggested delayed radiation injury. Magnetic resonance imaging demonstrated signal changes and edema surrounding the radiosurgical target. Dose-volume guidelines for avoiding complications were constructed. Our initial experience indicates that stereotactic radiosurgery can be performed safely in patients with small, well-circumscribed AOVMs located in deep, critical, or relatively inaccessible cerebral locations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Gamma knife radiosurgery for intracranial arteriovenous malformations in childhood and adolescence.

Eighteen children or adolescents with intracranial arteriovenous malformations (AVM) underwent stereotactic radiosurgery using the first North American gamma knife. This closed-skull, single-treatment therapy, utilizing 201 ionizing beams of gamma-irradiation, was used as an alternative to microsurgical removal in these selected patients (aged 34 months to 18 years, mean 12.3 years) beginning in August 1987. No significant perioperative morbidity occurred, and no patient rebled or died in the follow-up interval ranging between 7 and 19 months. Computed tomography (CT) and magnetic resonance imaging (MRI) were used to monitor the response to treatment and to determine when postoperative angiography was indicated. Of seven AVMs examined with cerebral angiography 1 year after treatment, three were completely obliterated; three others were significantly smaller, and their complete obliteration is anticipated by 2 years after treatment. Follow-up CT or MRI confirmed attenuation or signal changes suggestive of edema surrounding the treatment volume in 3 patients; 1 had transient worsening of a preexisting neurological deficit. Although a more long-term perspective is still required for this new technology now available in the United States, we believe that gamma knife stereotactic radiosurgery is a safe and effective method to obliterate AVM deemed too risky for microsurgical removal.

Adolescent↗
PubMed1988

Bilateral trigeminal neuralgia: a 14-year experience with microvascular decompression.

Thirty-five patients with trigeminal neuralgia (TN) bilaterally underwent posterior fossa microvascular decompression (MVD) between 1971 and 1984. They comprised 5.0% of a larger series of 699 patients with TN who underwent MVD during that interval. Compared to the subgroup of 664 patients with only unilateral symptoms, the population with bilateral TN included a greater percentage of females (74% vs. 58%, p less than 0.1), a higher rate of "familial" TN (17% vs. 4.1%, p less than 0.001), and an increased incidence of additional cranial nerve dysfunction (17% vs. 6.6%, p less than 0.05) and hypertension (34% vs. 19%, p less than 0.05). Of the 35 patients with bilateral TN, 10 underwent bilateral MVD (22 procedures) and 25 underwent unilateral MVD (30 procedures). In the latter patients, pain on the nonoperative side was well controlled with medication alone or had previously been treated by ablative procedures. Good or excellent pain control was achieved after one MVD was performed in 40 of the 45 sides treated (89%), and was maintained 1, 5, and 10 years after surgery in 82%, 66%, and 60%, respectively, based on life-table analysis. Six of 10 patients with recurrent symptoms underwent repeat unilateral MVD. Good or excellent long-term pain control was maintained in all six. With these repeat procedures included, symptom control at 1, 5, and 10 years after initial surgery was maintained in 87%, 78%, and 78% of the treated sides, respectively. Overall, 26 of 35 patients (74%) maintained good or excellent pain relief throughout the duration of the study (mean follow-up period 75 months) without resumption of regular medication usage. Although preoperative neurological deficits resulting from previous ablative procedures were seen in the majority of patients before MVD, no patient developed new major trigeminal sensory loss or masseter weakness after MVD. Operative mortality was zero. The results indicate that posterior fossa MVD is an effective and relatively safe treatment for the majority of patients with bilateral "idiopathic" TN, avoiding the risks of bilateral trigeminal nerve injury seen with other approaches.

Cerebellopontine Angle↗
PubMed1980

Anterior surgery for cervical disc disease. Part 1: Treatment of lateral cervical disc herniation in 253 cases.

Between 1971 and 1977, 334 patients at the Presbyterian-University Hospital underwent anterior surgery for treatment of hard or soft cervical disc herniation. Of these patients, 295 had radicular symptoms only. This retrospective study details the results of anterior cervical surgery for treatment of lateral disc herniation in 253 patients who survived 1 to 7 years postoperatively. Sixty-seven percent had excellent or good results. Although 77% initially noted complete relief of symptoms after surgery, 38% subsequently developed one or more recurrent symptoms at some time during the follow-up period. The overall results of surgery for soft disc cases were no different from the results for hard discs, although significantly more hard disc cases required postoperative conservative treatment. The results of surgery after anterior fusion were no different than the results after anterior discectomy alone. However, overall postoperative complications were more frequent and hospitalizations were longer in the patients who underwent fusion. Patients with multiple-level surgery had statistically similar results to those with single-level surgery. None of the nine preoperative clinical features reported by others to influence the results of anterior cervical surgery were found to consistently affect outcome in the present series.

Adult↗
PubMed1980

Anterior surgery for cervical disc disease. Part 2: Treatment of cervical spondylotic myelopathy in 32 cases.

The results of anterior cervical surgery for treatment of cervical spondylotic myelopathy (CSM) are assessed 1 to 7 years postoperatively in 32 patients. At follow-up review, 50% were improved after surgery and 50% were unimproved or had deteriorated in spite of surgery. The results could not be statistically linked to the patients' age, duration of symptoms, severity of myelopathy, cervical canal size, or the performance of single- or multiple-level operations. Various anterior surgical techniques were used, but none proved to have superior results. The results in this series failed to surpass the results obtained by others for conservative treatment alone. In many cases, symptoms of CSM progressed despite the intervention of anterior cervical surgery.

Adult↗
PubMed1978

Bell's palsy: a theory as to etiology. Observations in six patients.

The etiology of Bell's palsy, like a number of other cranial nerve afflictions which consist of rapid or sudden loss of function, has never been satisfactorily explained despite extensive analysis by a number of investigators over the years. These entities may have a simple mechanical explanation in some patients. This consists of the sudden shift of an arterial loop in the cerebellopontine angle stretching the appropriate nerve. In Bell's palsy, the facial-acoustic nerve bundle appears to be stretched and compressed from the anterior aspect. Operative findings showing these abnormalities have been demonstrated in six patients and treated in five. A clinical-pathological analysis of the events of the history and findings in this modest series of patients with Bell's palsy appears to correlate clearly with such a cause.

Adult↗